Father and son appeared in court for preliminary hearing of Kristin Smart case

The murder suspect of Kristin Smart and his father appeared in court for the preliminary hearing in San Luis Obispo County on Monday. 

Paul Flores, 44, was the last person seen with Smart on May 24,1996. He was accused of killing Smart during an attempted rape in his dorm room at Cal Poly.

His father, Ruben Flores, was accused of helping his son hide Smart's body. 

San Luis Obispo County Sheriff's Department alleged that Smart was once buried under his deck in nearby Arroyo Grande after new biological evidence was uncovered this year. 

Smart's body was never found. 

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Both suspects had pleaded not guilty to their charges. 

Kristin Smart's mother, Denise, was the first witness to take the stand on Monday. 

The preliminary hearing is expected to last three weeks.